I was working on mounting the motor and found a couple of items. NOTE -- I'm not using the recommended motor, so some of these issues may not apply if you use the Model Aero motor.

First, my motor shaft extended out behind the motor mount too far and it hit the plywood motor pylon brace. Rather than cut out the plywood, I shortened my motor shaft.

Second, I measured the distance from the firewall to the end of the plastic cowl and found that I needed 1-7/8" (48mm) for the prop to clear the front of the cowl. For my motor, I needed to add 3/8" spacers for the prop to clear, or I guess I could have cut 3/8" off the cowl.

So far, I'm very happy with my purchase. Now I need to get back to work.

McD

Kingsflyer, we sized the plastic cowl specifically for the recommended 2810-9 motor, while realizing other motors may require some trimming or shimming as yours did.

Can you share what motor you are using? The 2810-9 motor on 4S pulls about 420 watts with an 8 x 4 prop.

Turns out my Christmas present did not get ordered yet, so my present under the tree will likely be a card with a receipt on it. But it's now on the website so easier for my wife to navigate and accomplish.

looks very cool, I have a kit built polaris and an electric northstar. Would like to see some more water take off videos before I pull the trigger. The only water video I have seen so far looks a little twitchy on fast taxi. The flier might just not be holding a little up, so hard to tell.

In flight video looks very good. As far as wire size goes, it's hard to argue with the people that have flown it already. I suppose a lower KVA motor with a 4 cell pack would drop the WOT amps some, but it looks like a non issue.

looks very cool, I have a kit built polaris and an electric northstar. Would like to see some more water take off videos before I pull the trigger. The only water video I have seen so far looks a little twitchy on fast taxi. The flier might just not be holding a little up, so hard to tell.

In flight video looks very good. As far as wire size goes, it's hard to argue with the people that have flown it already. I suppose a lower KVA motor with a 4 cell pack would drop the WOT amps some, but it looks like a non issue.

In that video Tim is running a 4S 2600 battery, so it's a pretty heavy setup and the plane is sitting lower in the water. Notice when he throttles up the torque tips the plane to the left and the left wingtip catches and then he over-corrects a little and catches the right wingtip. Once it's fully "on step" it's off to the races.

I have noticed when flying her off water you can avoid this by simply keeping the wings level with aileron to offset the torque effect until she's on step.

Kingsflyer
Can you share what motor you are using? The 2810-9 motor on 4S pulls about 420 watts with an 8 x 4 prop.
Scott

Hey Scott,

I wish I had the motor info, but I think it's a Grim Reaper of some sort. I bought it at the 3DHS closeout sale a while back. I think the kV must be lower than your 2810-9 motor because it only pulled 415 watts with the 8x6 on 4-cells. It weighs 75 grams so it should work I think.

I was concerned that here in Texas in the summertime, I might need some extra motor cooling. I see the openings in the front of the cowl, but there doesn't seem to be any opening for the air to exit the cowl area. I was planning to cut out an area on the bottom of cowl to provide an air exit and also allow any ingested water a way to drain out.

I have discovered that just like so many other foamies, the Ultra's paint is a little fragile. I tried using the low tack Blue painters tape when I was installing the canopy, but it still pulled off some of the paint. I think that it's just a fact of life that foam doesn't allow much of a purchase for paint to adhere to its surface. It's not a disaster, it's just a reality with foam ARFs.

I hope that my comments are not misinterpreted. They are all intended to be constructive and I hope they can help other builders. I really like my new Ultra and I can't wait to get her airborne!

I wish I had the motor info, but I think it's a Grim Reaper of some sort. I bought it at the 3DHS closeout sale a while back. I think the kV must be lower than your 2810-9 motor because it only pulled 415 watts with the 8x6 on 4-cells. It weighs 75 grams so it should work I think.

I was concerned that here in Texas in the summertime, I might need some extra motor cooling. I see the openings in the front of the cowl, but there doesn't seem to be any opening for the air to exit the cowl area. I was planning to cut out an area on the bottom of cowl to provide an air exit and also allow any ingested water a way to drain out.

I have discovered that just like so many other foamies, the Ultra's paint is a little fragile. I tried using the low tack Blue painters tape when I was installing the canopy, but it still pulled off some of the paint. I think that it's just a fact of life that foam doesn't allow much of a purchase for paint to adhere to its surface. It's not a disaster, it's just a reality with foam ARFs.

I hope that my comments are not misinterpreted. They are all intended to be constructive and I hope they can help other builders. I really like my new Ultra and I can't wait to get her airborne!

McD

That motor should be a screamer. I've actually flown the Ultra on 220 watts up to 420 watts, and I can tell you 415 watts will really get her moving.

I've found the same thing with paint on foam ARF'S, especially ones molded from EPO. It's by far the best foam, but there are release agents used during the molding process that can inhibit the paint from sticking well. As long as you're careful it's fine. Mine still looks great after many flights.

I've found the same thing with paint on foam ARF'S, especially ones molded from EPO. It's by far the best foam, but there are release agents used during the molding process that can inhibit the paint from sticking well. As long as you're careful it's fine. Mine still looks great after many flights.

Scott

Most polyolefin do not accept finishes without some kind of pre treatment
to etch the surface. It does not have as much to do with the release used as it does to the material composition itself which has a natural lubricity.

Flame or plasma surface treatment may possibly deform the foam but there are special ink compositions for printing on treated or untreated surfaces of polyolefin plastics.

The manufacturer could possibly find a paint or ink that will adhere better.